From owner-freebsd-usb@FreeBSD.ORG Mon Aug 14 12:29:27 2006 Return-Path: X-Original-To: freebsd-usb@freebsd.org Delivered-To: freebsd-usb@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DCBC316A4E2 for ; Mon, 14 Aug 2006 12:29:27 +0000 (UTC) (envelope-from admin@intron.ac) Received: from intron.ac (unknown [210.51.165.237]) by mx1.FreeBSD.org (Postfix) with ESMTP id 55EC443D81 for ; Mon, 14 Aug 2006 12:29:18 +0000 (GMT) (envelope-from admin@intron.ac) Received: from localhost (localhost [127.0.0.1]) (uid 1003) by intron.ac with local; Mon, 14 Aug 2006 20:29:16 +0800 id 00102C04.44E06C9C.000024BE References: <44DF8308.9080700@fernuni-hagen.de> <6.2.3.4.0.20060813170759.12be7730@64.7.153.2> <44E00CFE.5090806@fernuni-hagen.de> <44E053CE.4090304@fernuni-hagen.de> In-Reply-To: <44E053CE.4090304@fernuni-hagen.de> From: "Intron" To: Marc van Woerkom Date: Mon, 14 Aug 2006 20:29:16 +0800 Mime-Version: 1.0 Content-Type: text/plain; charset="gb2312"; format=flowed Content-Transfer-Encoding: 7bit Message-ID: Cc: freebsd-usb@freebsd.org Subject: Re: SD card speed X-BeenThere: freebsd-usb@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: FreeBSD support for USB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 14 Aug 2006 12:29:28 -0000 Marc van Woerkom wrote: > Intron wrote: >> Have you tested your card reader on Microsoft Windows? >> FreeBSD's FAT module probably isn't optimized enough. >> > No, but what I just tried again,after I formatted > the SD card under Windows. > > Guess what happened: > > tty da2 cpu > tin tout KB/t tps MB/s us ni sy in id > 0 64 4.00 483 1.89 10 0 17 13 60 > 0 161 4.00 486 1.90 16 0 13 12 59 > 0 43 4.00 477 1.86 9 0 14 8 70 > 0 65 4.00 422 1.65 8 0 15 9 69 > 0 78 4.00 486 1.90 5 0 11 13 71 > 0 43 4.00 485 1.89 4 0 5 8 83 > 0 121 4.00 474 1.85 10 0 14 9 67 > 0 43 4.00 486 1.90 8 0 16 11 65 > 0 43 4.00 483 1.89 16 0 6 9 69 > 0 43 4.00 396 1.55 7 0 16 9 69 > 0 65 4.00 484 1.89 9 0 14 10 67 > 0 43 4.00 482 1.88 7 0 16 13 63 > 0 43 4.00 485 1.89 5 0 14 12 69 > 0 43 4.00 318 1.24 6 0 9 13 71 > 136 43 4.00 482 1.88 9 0 16 6 69 > > Thus the crucial factor is the formatting! > Try to run "chkdsk" against your card under Microsoft Windows XP. Chkdsk will report file system type (FAT16 or FAT32) and cluster size (e.g. 16384 bytes) after checking file system on your SD card. Format your SD card with the same file system type (-F) and cluster size (-b) under FreeBSD and test the transmission rate again. As I have referred to in my previous letter, I guess the difference of transmission rate comes from the asynchronous transmission mechanism and the sensibility against transmission on-line delay of USB, which is rather fit for large block transmission than small block transmission. ------------------------------------------------------------------------ From Beijing, China